1. Chapter 7 - Human Population Ecology
What is the history and future of human population #s?
How is population size affected by males vs. females, birth, death, fertility, and migration rates?
What successes have India and China had in slowing population growth?
An expanding human population represents the greatest threat to the world’s ecosystems
Demographic transitions explain population and economic changes as countries develop.
Population debates must consider economic growth, politics, religions, personal freedom and moral beliefs.

2. 1. - Is the World Overpopulated?
Most demographers say yes.
Technological Optimists – growth can be supported. Are longer life spans evidence of this?
Thomas Malthus, 1798 – linear food would limit exponential population.
Paul Ehrlich, 1968 – Predicted problems too soon!!
Malthus – English scholar and cleric, political economist. Population would be checked by famine and disease.

3. 2. - POPULATION GROWTH HISTORY:
Why has population grown rapidly?
Physical expansion
Agriculture expansion
Industrial production
Hygiene and medicine

4. Earth adds ~¼ million every day.
Optimum Sustainable Earth Population – max. without impairing planet from sustaining future generations.
Developed countries: 0.1% per year.
Developing countries: 1.5% per year. (97% of growth)
There is a maximum population, but that is not optimum if you consider quality of life issues

5. 3. - POPULATION SIZE CHANGES
Net Migration = difference per 1000.
Crude birth and death rates (CBR & CDR) (per 1000 people)
Remember doubling rule?...
70 / % rate = years to double

6. A. Factors Affecting Birth & Death Rates
Births: Education, Employment; Marriage Age; Abortion and Contraception availability; Cultural issues; Women’s rights.
Deaths: Better nutrition, medicine, sanitation, Age Structure.
Infant Mortality - # die before 1st birthday (per 1000). Quality of Life standard. U.S. ranks ~46th world-wide – why not #1?
highest (developed) teenage birth rate
Inadequate pre- and post-natal care for poor.
Drug addiction.

7. B. Total Fertility Rate (TFR): avg. # of children a woman has.
C. Replacement Level Fertility: = 2 (couple replaces themselves).
Declining Fertility – births dropping, but not enough to stabilize population.
Global replacement rate is 2.1
U.N. projections based on avg. of 2.5, 2.0, or 1.5 children per woman.

8. U.S. = + 3 million each year:
~60% = CBR-CDR.
~40% = immigration.
Why did baby bust follow baby boom?
Delayed marriage
Contraception
Abortion
Economics

9. 2013, avg. global Total Fertility Rate = 2.3 children per woman.
1.6 in developed countries (down from 2.5 in 1950).
3.0 in developing countries (down from 6.5 in 1950).

10. 4. - POPULATION AGE STRUCTURE
# of Males/Females in each age group.
“Pyramids” graphically illustrate population status.
Changes in age group distributions cause economic and social impacts. Like??
Chinese law – visit elderly
Strains the global economy. Why?
Less taxpayers, more retirees
Less new technology and businesses

11. Population momentum – despite controls, growth continues.
Pyramid = pop # at each age.
Large youth # = potential for rapid growth.
Population momentum – despite controls, growth continues.

12. Disease/War disrupts social and economic structure - removes young adults.

13. 5. - Demographic Transition:
Development = decline in birth and death rates.
Preindustrial stage: high birth rates. Little population growth due to infant mortality.
Transitional stage: industrialization begins, death rates drops and birth rates remain high.
Industrial stage: birth rate drops, approaches death rate.
Post-Industrial: population decreases. ZPG

14. “Developed” women tend to have fewer children if they are?
Educated.
Hold a job.
Financially secure.
Enjoy equal rights.

15. Some developing countries may have difficulty making the demographic transition. Why?

16. 6. - INDIA vs. CHINA Populations
India – why limited success controlling population?
China – one child program very effective.

17. China’s Status TFR ~1.6 children (per woman). Problems: Momentum
Strong male preference = gender imbalance.
Average population age is increasing.
Not enough resources.

18. 7. - HUMAN IMPACTS ON NATURAL SYSTEMS
Impact= Population X Affluence X Technology